Proton is one of the brands that focuses on privacy, and offers several services under them, such as Proton Mail, Proton VPN and also Proton Drive. Most recently, they announced the acquisition of Standard Notes, adding a note-taking application under their product portfolio.
Standard Notes offers full encryption support, and is offered on several platforms, including desktop, and mobile applications. It has been offered since last 2017, and has around 300,000 active users worldwide.
Despite being taken over by Proton, Standard Notes will continue to operate independently, and be offered as open source. Proton aims to integrate Standard Notes under the ecosystem in the future.
For those of you who are interested, you can try Standard Notes for free today, and use it to store and record various types of notes.